O Schmitt

University of Rostock, Rostock, Mecklenburg-Vorpommern, Germany

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Publications (191)342.85 Total impact

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    ABSTRACT: In this study, we searched for proteins that change their expression in the olfactory bulb (oB) of rats during ontogenesis. Up to now, protein expression differences in the developing animal are not fully understood. Our investigation focused on the question whether specific proteins exist which are only expressed during different development stages. This might lead to a better characterization of the microenvironment and to a better determination of factors and candidates that influence the differentiation of neuronal progenitor cells. After analyzing the samples by two-dimensional polyacrylamide gel electrophoresis (2DE) and matrix-assisted laser desorption/ionization time-of-flight mass spectrometry (MALDI-TOF-MS), it could be shown that the number of expressed proteins differs depending on the developmental stages. Especially members of the functional classes, like proteins of biosynthesis, regulatory proteins and structural proteins, show the highest differential expression in the stages of development analyzed. In this study, quantitative changes in the expression of proteins in the oB at different developmental stages (postnatal days (P) 7, 90 and 637) could be observed. Furthermore, the expression of many proteins was found at specific developmental stages. It was possible to identify these proteins which are involved in processes like support of cell migration and differentiation.
    Proteome Science 01/2015; 13:8. · 1.88 Impact Factor
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    ABSTRACT: The basal ganglia of the laboratory rat consist of a few core regions that are specifically interconnected by efferents and afferents of the central nervous system. In nearly 800 reports of tract-tracing investigations the connectivity of the basal ganglia is documented. The readout of connectivity data and the collation of all the connections of these reports in a database allows to generate a connectome. The collation, curation and analysis of such a huge amount of connectivity data is a great challenge and has not been performed before (Bohland et al. PloS One 4:e7200, 2009) in large connectomics projects based on meta-analysis of tract-tracing studies. Here, the basal ganglia connectome of the rat has been generated and analyzed using the consistent cross-platform and generic framework neuroVIISAS. Several advances of this connectome meta-study have been made: the collation of laterality data, the network-analysis of connectivity strengths and the assignment of regions to a hierarchically organized terminology. The basal ganglia connectome offers differences in contralateral connectivity of motoric regions in contrast to other regions. A modularity analysis of the weighted and directed connectome produced a specific grouping of regions. This result indicates a correlation of structural and functional subsystems. As a new finding, significant reciprocal connections of specific network motifs in this connectome were detected. All three principal basal ganglia pathways (direct, indirect, hyperdirect) could be determined in the connectome. By identifying these pathways it was found that there exist many further equivalent pathways possessing the same length and mean connectivity weight as the principal pathways. Based on the connectome data it is unknown why an excitation pattern may prefer principal rather than other equivalent pathways. In addition to these new findings the local graph-theoretical features of regions of the connectome have been determined. By performing graph theoretical analyses it turns out that beside the caudate putamen further regions like the mesencephalic reticular formation, amygdaloid complex and ventral tegmental area are important nodes in the basal ganglia connectome. The connectome data of this meta-study of tract-tracing reports of the basal ganglia are available for further network studies, the integration into neocortical connectomes and further extensive investigations of the basal ganglia dynamics in population simulations.
    Brain Structure and Function 11/2014; · 7.84 Impact Factor
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    ABSTRACT: Niemann-Pick type C1 (NPC1) disease is a lysosomal storage disease characterized by a deficiency of NPC1 gene function. The malfunction of protein results in a progressive accumulation of lipids in many organs. A combined approach with substrate-reduction therapy (SRT) and byproduct therapy (BPT) has been shown to ameliorate the disease course in a mutant mouse model (NPC1–/–). The present study examines the morphological parameters underlying these changes. For the combined SRT/BPT treatment, NPC1–/– mutant mice (NPC1–/–SRT/BPT) were injected with allopregnanolone/cyclodextrin weekly, starting at postnatal day (P) 7. Starting at P10, a miglustat injection was administered daily until P23. Thereafter, miglustat was added to the powdered chow. For the sham treatment, both mutant NPC1–/– (NPC1–/–sham) and wild-type (NPC1+/+sham) mice received an NaCl injection and were fed powdered chow without miglustat. Analysis was performed on cerebellar slices by histology and immunohistochemistry. The volumes and cell counts of cerebellar structures were quantified. Additionally, ultrastructural analysis was performed with transmission electron microscopy. In agreement with previous studies, the current study demonstrates Purkinje cell degeneration in the mutant mice, which was partially abrogated by SRT/BPT. The volumes of cerebellar white matter and molecular layer were reduced as well. Also, the number of neurons was reduced in granular and molecular layers. However, only the molecular layer benefited from the therapy, as shown by an increase in the volume and the amount of neurons. The volume and number of neurons of the deep cerebellar nuclei were significantly decreased in mutant mice; an appreciable therapeutic benefit could be demonstrated for the nucleus interpositus. © 2014 Wiley Periodicals, Inc.
    Journal of Neuroscience Research 11/2014; 93(3). · 2.73 Impact Factor
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    ABSTRACT: The treatment of Parkinson's disease by transplantation of dopaminergic (DA) neurons from human embryonic mesencephalic tissue is a promising approach. However, the origin of these cells causes major problems: availability and standardization of the graft. Therefore, the generation of unlimited numbers of DA neurons from various types of stem or progenitor cells has been brought into focus. A source for DA neurons might be conditionally immortalized progenitor cells. The temperature-sensitive immortalized cell line CSM14.1 derived from the mesencephalon of an embryonic rat has been used successfully for transplantation experiments. This cell line was analyzed by unbiased stereology of cell type specific marker proteins and 2D-gel electrophoresis followed by mass spectrometry to characterize the differentially expressed proteome. Undifferentiated CSM14.1 cells only expressed the stem cell marker nestin, whereas differentiated cells expressed GFAP or NeuN and tyrosine hydroxylase. An increase of the latter cells during differentiation could be shown. By using proteomics an explanation on the protein level was found for the observed changes in cell morphology during differentiation, when CSM14.1 cells possessed the morphology of multipolar neurons. The results obtained in this study confirm the suitability of CSM14.1 cells as an in vitro model for the study of neuronal and dopaminergic differentiation in rats.
    BioMed research international. 01/2014; 2014:351821.
    This article is viewable in ResearchGate's enriched format
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    ABSTRACT: Compression of the ulnar nerve at Guyon's canal can be caused not only by tumor-like structures, a fibrotic arch, a ganglion, lipoma, aneurysm or thrombosis but also by anomalous hypothenar muscles which are reviewed here. For the search of relevant papers, PubMed and crucial anatomical textbooks were consulted. The abductor digiti minimi is the most variable hypothenar muscle. It can possess one to three muscle bellies. Additional heads can arise from the flexor retinaculum, the palmaris longus tendon, the pronator quadratus tendon or the deep fascia of the palmar side of the forearm. Our own case of an aberrant abductor digiti minimi appearing like connective tissue and originating in the antebrachial fascia is included here. Hematoxylin and eosin staining revealed that macroscopically non-muscle-like tissue contained skeletal muscle tissue. The muscle itself resembled other described cases. In addition, at the flexor digiti minimi accessory heads with origin from the flexor retinaculum, the antebrachial fascia or the long flexor muscles of the forearm can be detected. By contrast, the opponens digiti minimi mostly lacks variations and is sometimes missing. In our opinion, this is due to its hidden location. However, in few cases an additional head can arise from the lower arm aponeurosis. Furthermore, additional (fourth) hypothenar muscles might be expressed. These muscles are characterized by origins in the forearm and insertions on the head of the 5th metacarpal bone or on the 5th proximal phalanx. It must be noted that accessory hypothenar muscles might look like connective tissue at first glance. Often their origin extends to the antebrachial fascia. This can be explained by the phylogenetic fact that all intrinsic muscles of the hand are derived from muscle masses that originated in the forearm. In the opinion of several authors, ulnar nerve compression mostly is evoked by hyper trophied variant hypothenar muscles due to overuse as for example in carpenters. In some rare cases, an aberrant hypothenar muscle can also evoke median nerve compression.
    Anatomia Clinica 04/2013; 35(10). · 1.33 Impact Factor
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    ABSTRACT: Botulinum neurotoxin (BoNT) inhibits the release of acetylcholine from presynaptic vesicles through its proteinase activity cleaving the SNARE complex. Parkinson's disease (PD) is associated with locally increased cholinergic activity in the striatum. Therefore, the present study investigates the effect of unilateral intrastriatal BoNT-A injection in naïve rats on striatal morphology; i.e., the total number of Nissl-stained neurons and the volume of caudate-putamen (CPu) were estimated. Furthermore, stainings for markers of gliosis (glial fibrillary acidic protein) and microglia (Iba1) were performed. In addition, the potential beneficial effects of a unilateral intrastriatal injection of BoNT-A on motor activity in the rat model of hemi-PD were evaluated. Hemi-PD was induced by unilateral injection of 6-hydroxydopamine (6-OHDA) into the right medial forebrain bundle. Six weeks later, rats received an ipsilateral intrastriatal injection of BoNT-A. Behaviorally, motor performance was tested. The total number of CPu neurons and the striatal volume were not significantly different between the BoNT-A-injected right and the intact left hemispheres of naïve rats. In hemi-PD rats, intrastriatal BoNT-A abolished apomorphine-induced rotations, increased amphetamine-induced rotations, and tended to improve left forelimb usage. Forced motor function in the accelerod test was not significantly changed by BoNT-A, and open field activity was also unaltered compared with sham treatment. Thus, intrastriatal BoNT-A affects spontaneous motor activity of hemi-PD rats to a minor degree compared with drug-induced motor function. In the future, tests assessing the cognitive and emotional performance should be performed to ascertain finally the potential therapeutic usefulness of intrastriatal BoNT-A for PD. © 2013 Wiley Periodicals, Inc.
    Journal of Neuroscience Research 03/2013; · 2.73 Impact Factor
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    ABSTRACT: The use of Botulinum neurotoxins (BoNTs) for therapeutic purposes in neuromuscular disorders and peripheral hypercholinergic conditions as well as in aesthetic medicine is widespread and common. BoNTs are also able to block the release of a wide range of transmitters from presynaptic boutons. Therefore, applications of BoNTs directly in the central nervous system (CNS) are currently under study with respect to basic research and potentially as new therapeutic strategies of neurological diseases. Investigations concentrate on effects of intracerebral and intraspinal applications of BoNTs in rodents on the impact on spinal, nuclear, limbic and cortical neuronal circuits. In respective animal models first promising BoNT-induced therapeutical benefits have been shown in the treatment of pain, epilepsy, stroke and Parkinson's disease.
    Current pharmaceutical biotechnology 10/2012; · 3.40 Impact Factor
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    ABSTRACT: Functional replacement of specific neuronal populations through transplantation of neural tissue represents an attractive therapeutic strategy for treating neurodegenerative disorders like Parkinson's disease (PD). Even though the brain is a partially immune privileged site, immunosuppression is still needed for the prevention of host immune response, and thus, xenograft rejection. Here, we investigated the fate of human ventral mesencephalon derived immortalized cell line ReNcell VM upon unilateral transplantation into the intact rat striatum with or without immunosuppression with cyclosporine A (CsA). The status of xenografted human ReNcell VM cells was analysed by immunohistochemistry/immunofluorescence 4 and 6weeks after transplantation. Four weeks after transplantation, ReNcell VM cells could be detected in both groups, although the number of survived cells was significantly higher in brains of immunosuppressed rats. In contrast, only 2 out of 6 brains grafted without immunosuppression revealed human ReNcell VM cells 6weeks post grafting, whereas a considerable number of human cells could still be found in all the brains of immunosuppressed rats. Immunohistochemical analysis of grafted cells showed almost no evidence of neuronal differentiation, but rather astroglial development. In summary, we have shown that the immunosuppression is needed for the survival of human VM derived progenitor cells in the rat striatum. CsA affected cell survival, but not differentiation capacity: in both groups, grafted either with or without immunosuppression, the ReNcell VM cells lacked neuronal phenotype and developed preferentially into astroglia.
    Annals of anatomy = Anatomischer Anzeiger: official organ of the Anatomische Gesellschaft 05/2012; 194(5):429-35. · 1.96 Impact Factor
  • L. Perlick, V. Rolf, T. Wallny, O. Schmitt
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    ABSTRACT: Bei der fibrösen Dysplasie finden sich in seltenen Fällen, sowohl bei der mono- als auch polyostotischen Form, eine Beteiligung der Halswirbelsäule (HWS). In der Mehrzahl handelt es sich um Zufallsbefunde im Rahmen der radiologischen Diagnostik. Es wird ein symptomatischer Fall mit atlantoaxialer Instabilität bei Befall des 1., 2. und 3. Halswirbelkörpers vorgestellt. Im Fall einer 53 jährigen Patientin, bei der seit 3 Monaten eine zervikale Myelopathie vorlag, wurde anhand von Nativröntgenaufnahmen und CT-Untersuchung eine zervikale fibröse Dysplasie diagnostiziert. Als Ursache der Symptomatik lag eine atlantoaxiale Instabilität vor. Es erfolgte eine dorsale Stabilisierung mit dem DCS-System. Fibrous dysplasia, in either monostotic or poliostotic form rarely involves the cervical spine. Most of these lesions remain asymtomatic and are incidental radiographic findings. A symptomatic case of polyostotic fibrous dysplasia involving the first, second and third cervical vertebra with potentially serious consequences is presented. A 53-year old woman who had shown cervical myelopathy for about 3 month was diagnosed as having cervical dysplasia on the basis of plain x-ray and CT scanning. In addition, atlanto-axial instability causing clinical symptoms was detected. A dorsal stabilisation was perfomed using the DCS System.
    Der Unfallchirurg 04/2012; 103(1):73-75. · 0.61 Impact Factor
  • Oliver Schmitt, Peter Eipert
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    ABSTRACT: neuroVIISAS is a generic platform which allows the integration of neuroontologies, mapping functions for brain atlas development, and connectivity data administration; all of which are required for the analysis of structurally and neurobiologically realistic simulations of networks. What makes neuroVIISAS unique is the ability to integrate neuroontologies, image stacks, mappings, visualizations, analyzes and simulations to use them for modelling and simulations. Based on the analysis of over 2020 tracing studies, atlas terminologies and registered histological stacks of images, neuroVIISAS permits the definition of neurobiologically realistic networks that are transferred to the simulation engine NEST. The analysis on a local and global level, the visualization of connectivity data and the results of simulations offer new possibilities to study structural and functional relationships of neural networks. This paper describes the major components and techniques of how to analyse, visualize and simulate with neuroVIISAS shown on a model network at a coarse CNS level (106 regions, 1566 connections) out of 13681 regions and 134043 connections of the left and right part of the CNS. This network of major components of the left and right hemisphere has small-world properties of the Watts-Strogatz model. Furthermore, synchronized subpopulations, oscillations of rate distributions and a time shift of population activities of the left and right hemisphere were observed in the neurocomputational simulations. In summary, a generic platform has been developed that realizes data-analysis-visualization integration for the exploration of network dynamics on multiple levels.
    Neuroinformatics 02/2012; 10(3):243-67. · 3.14 Impact Factor
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    ABSTRACT: The connectomes of nervous systems or parts there of are becoming important subjects of study as the amount of connectivity data increases. Because most tract-tracing studies are performed on the rat, we conducted a comprehensive analysis of the amygdala connectome of this species resulting in a meta-study. The data were imported into the neuroVIISAS system, where regions of the connectome are organized in a controlled ontology and network analysis can be performed. A weighted digraph represents the bilateral intrinsic (connections of regions of the amygdala) and extrinsic (connections of regions of the amygdala to non-amygdaloid regions) connectome of the amygdala. Its structure as well as its local and global network parameters depend on the arrangement of neuronal entities in the ontology. The intrinsic amygdala connectome is a small-world and scale-free network. The anterior cortical nucleus (72 in- and out-going edges), the posterior nucleus (45), and the anterior basomedial nucleus (44) are the nuclear regions that posses most in- and outdegrees. The posterior nucleus turns out to be the most important nucleus of the intrinsic amygdala network since its Shapley rate is minimal. Within the intrinsic amygdala, regions were determined that are essential for network integrity. These regions are important for behavioral (processing of emotions and motivation) and functional (memory) performances of the amygdala as reported in other studies.
    Frontiers in Neural Circuits 01/2012; 6:81. · 2.95 Impact Factor
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    ABSTRACT: The orexinergic system interacts with several functional states of emotions, stress, hunger, wakefulness and behavioral arousal through four pathways originating in the lateral hypothalamus (LH). Hundreds of orexinergic efferents have been described by tracing studies and direct immunohistochemistry of orexin in the forebrain, olfactory regions, hippocampus, amygdala, septum, basal ganglia, thalamus, hypothalamus, brain stem and spinal cord. Most of these tracing studies investigated the whole orexinergic projection to all regions of the intracranial part of the CNS. To identify the orexinergic efferents at the subnuclear level of resolution, we focussed on the orexinergic target in the amygdala, which is substantially involved in the LH output and contributes mostly to the functional outcome of the orexinergic system and the basal ganglia. Immunohistochemical identification of axonal orexin A and orexin B in male adult rats has been performed on serial sections. In the extended amygdala many new orexinergic targets were found in the anterior amygdaloid area (dense), anterior cortical nucleus (moderate), amygdalostriatal transition region (moderate), basolateral regions (moderate), basomedial nucleus (moderate), several bed nucleus of the stria terminals regions (few to dense), central amygdaloid subdivisions (dense), posteromedial cortical nucleus (moderate) and medial amygdaloid subnuclei (dense). Furthermore, the entopeduncular nucleus has been newly identified as another target for orexinergic fibers with a high density. These results suggest that subdivisions and subnuclei of the extended amygdala are specific targets of the orexinergic system.
    Brain Structure and Function 09/2011; 217(2):233-56. · 7.84 Impact Factor
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    ABSTRACT: Due to enormous advances in quantitative proteomics and in immunohistochemistry (pathology), the two research areas have now reached the state to be successfully interwoven in order to tackle challenges in toponostics and to open tumor-targeted systems pathology approaches. In this study the differential expressions of candidate proteins nucleophosmin, nucleoside diphosphate kinase A/B (NDKA/B), osteoinducive factor (mimecan), and pyru-vate kinase M2 from a quantitative proteome signature for invasive ductal breast cancer were determined by immunohistochemistry on 53 tissue slices from formalin-fixed and paraffin-embedded tumor and control tissue samples from ten patients and fourteen controls. In addition, 87 images from the Human Protein Atlas representing seven tumor and nine normal breast tissue samples were investigated by computer-assisted semi-quantitative density measurements on nucleophosmin, nucleoside diphosphate kinase A/B (NDKA/B), osteoinducive factor (mimecan), pyruvate kinase M2, glyceraldehyde-3-phosphate dehydro-genase (GAP-DH), and mimecan (osteoinductive factor). Both IHC data sets match well to each other and support the quantitative proteome analysis data. Determining spatial distribution of signature protein expressions by protein imaging on morphologically intact tissue samples at the sub-cellular level and, hence, keeping all topological information, presents an added value to quantitative proteome data. Such comprehensive data sets are needed for both, pathway analyses and for "next generation clinical diagnostics" approaches.
    International journal of clinical and experimental pathology 03/2011; 4(5):454-67. · 1.78 Impact Factor
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    ABSTRACT: Previous neurophysiological studies have demonstrated that the amygdala has a direct influence upon trigeminal motoneuron activity. The existence of a direct amygdalotrigeminal pathway in rats was proved by anterograde tracing with the neuroanatomical tracer, biotinylated dextran amine (BDA). After ipsilateral BDA application to the central nucleus of the amygdala (AmCe), widespread ipsilateral projections emerging from its medial subnucleus were traced to the trigeminal brainstem nuclear complex, including the principal sensory (Pr5) and mesencephalic trigeminal nucleus (Me5), and their premotoneurons and interneurons, located in the supratrigeminal, intertrigeminal and peritrigeminal nuclei. Sparse BDA-labeled axons and their terminals were also distributed in the contralateral Pr5, interpolar and caudal subnuclei of the spinal trigeminal nucleus. The central lateral amygdaloid nucleus gives rise to a light ipsilateral projection to the pontine part of the Me5. The present data indicate that AmCe sends massive efferents to the trigeminal nuclei in the brainstem, wherein its medial subnucleus sends the major input to them. The medial amygdaloid nucleus sparsely innervates Me5 neurons, specifically those located in its mesencephalic portion, while basomedial and basolateral efferents do not target the trigeminal nuclear complex. These results suggest that the amygdaloid input may modulate the activity of trigeminal sensory and motor neurons and, thus, the amygdala is possibly involved in the control of masticatory behavior.
    Annals of anatomy = Anatomischer Anzeiger: official organ of the Anatomische Gesellschaft 03/2011; 193(2):118-26. · 1.96 Impact Factor
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    ABSTRACT: Hintergrund: Seit ca. 10 Jahren wird über Therapieversuche mit Applikation von Botulinumneurotoxinen (BoNTs) in das ZNS berichtet. Der Therapieeffekt wird sowohl auf anti-cholinerge als auch auf anti-glutamaterge und anti-GABAerge Wirkungen der BoNT-Isoformen zurückgeführt. Verschiedene Arbeitsgruppen behandelten folgende Krankheiten im Ratten- oder Mausmodell: Schmerz-Syndrome (BoNT-A und BoNT-B intraspinal bzw. intrathekal), Epilepsie und Schlaganfall (BoNT-E intrahippokampal), Morbus Parkinson (BoNT-A intrastriatal). Methoden: Eigene Untersuchungen wurden im Hemiparkinsonmodell der Ratte durchgeführt, das durch unilaterale Injektion von 6-Hydroxydopamin in das mediale Vorderhirnbündel induziert wurde. Die Ratten erhielten einmalig ipsilateral intrastriatal 1ng BoNT-A. Sie wurden über 1 Jahr mit Verhaltenstests zur Beurteilung der motorischen Funktionen (Rotationstest, Zylindertest, RotaRod-Test, Open-Field-Test) untersucht. Bei Kontrolltieren, die bilateral nur mit BoNT-behandelt wurden, kamen Labyrinth-Tests zur Beurteilung der Kognition und Emotion hinzu. Außerdem wurden serielle Hirnschnitte quantitativ histologisch (Nissl-Färbung), immunhistochemisch (Cholinacetyltransferase, ChAT; Tyrosinhydroxylase, TH) und ultramikroskopisch ausgewertet. Ergebnisse: Die pathologische Apomorphin-induzierte Rotation ist über mindestens 3 Monate komplett aufgehoben und über weitere 3 Monate signifikant reduziert. Auch der im Zylindertest gemessene asymmetrische Vorderpfotengebrauch verbessert sich über mindestens 3 Monate. In BoNT-behandelten gesunden Kontrolltieren ist weder das räumliche Arbeitsgedächtnis (Water-Maze-Test) noch das Langzeitgedächtnis (Radial-Maze-Test) beeinträchtigt. Das Angstverhalten (Bewegungsverhalten im Open-Field-Test und Elevated-Plus-Maze-Test) ist bei diesen Tieren reduziert. Immunhistochemisch gibt es keine signifikanten Zellzahlveränderungen in den BoNT-infiltrierten Striata. Es treten aber bisher nicht beschriebene axonale Varikositäten mit einem variablen Durchmesser von 2–9µm auf, die zahlreiche entweder ChAT- oder TH-positive Vesikel und vereinzelt Mitochondrien enthalten. Schlussfolgerungen: Zentral appliziertes BoNT erweitert die Behandlungsoptionen einer zunehmenden Zahl neurologischer Erkrankungen. Beim Morbus Parkinson könnten intrastriatale BoNT-A-Gaben sowohl motorische Dysfunktionen als auch Angststörungen und Depressionen positiv beeinflussen, ohne kognitive und periphere cholinerge Funktionen zu beeinträchtigen.
    Aktuelle Neurologie 01/2011; · 0.32 Impact Factor
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    BMC Neuroscience 01/2011; 12:1-2. · 2.85 Impact Factor
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    ABSTRACT: Human neural progenitor cells provide a source for cell replacement therapy to treat neurodegenerative diseases. Therefore, there is great interest in mechanisms and tools to direct the fate of multipotent progenitor cells during their differentiation to increase the yield of a desired cell type. We tested small molecule inhibitors of glycogen synthase kinase-3 (GSK-3) for their functionality and their influence on neurogenesis using the human neural progenitor cell line ReNcell VM. Here we report the enhancement of neurogenesis of human neural progenitor cells by treatment with GSK-3 inhibitors. We tested different small molecule inhibitors of GSK-3 i.e. LiCl, sodium-valproate, kenpaullone, indirubin-3-monoxime and SB-216763 for their ability to inhibit GSK-3 in human neural progenitor cells. The highest in situ GSK-3 inhibitory effect of the drugs was found for kenpaullone and SB-216763. Accordingly, kenpaullone and SB-216763 were the only drugs tested in this study to stimulate the Wnt/β-catenin pathway that is antagonized by GSK-3. Analysis of human neural progenitor differentiation revealed an augmentation of neurogenesis by SB-216763 and kenpaullone, without changing cell cycle exit or cell survival. Small molecule inhibitors of GSK-3 enhance neurogenesis of human neural progenitor cells and may be used to direct the differentiation of neural stem and progenitor cells in therapeutic applications.
    Neuroscience Letters 11/2010; 488(1):36-40. · 2.06 Impact Factor
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    ABSTRACT: Central pathophysiological pathways of basal ganglia dysfunction imply a disturbed interaction of dopaminergic and cholinergic circuits. In Parkinson's disease (PD) imbalanced cholinergic hyperactivity prevails in the striatum. Interruption of acetylcholine (ACh) release in the striatum by locally injected botulinum neurotoxin A (BoNT-A) has been studied in the rat 6-hydroxydopamine (6-OHDA) model of PD (hemi-PD). The hemi-PD was induced by injection of 6-OHDA into the right medial forebrain bundle. Motor dysfunction provoked by apomorphine-induced contralateral rotation was completely reversed for more than 3 months by ipsilateral intrastriatal application of 1-2 ng BoNT-A. Interestingly, BoNT-A injected alone into the right striatum of naïve rats caused a slight transient ipsilateral apomorphine-induced rotation, which lasted only for about one month. Immunohistochemically, large axonal swellings appeared within the striatum injected with BoNT-A, which we tentatively named BoNT-A-induced varicosities. They contained either choline acetyltransferase or tyrosine hydroxylase. These findings suggest a selective inhibition of evoked release of ACh by locally applied BoNT-A. Intrastriatal application of BoNT-A may antagonize localized relative functional disinhibited hypercholinergic activity in neurodegenerative diseases such as PD avoiding side effects of systemic anti-cholinergic treatment.
    Neurobiology of Disease 10/2010; 41(2):291-8. · 5.62 Impact Factor
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    ABSTRACT: Parkinson's disease is a multifactorial, neurodegenerative disease where etiopathogenetic mechanisms are not fully understood. Animal models like the neurotoxic 6-OHDA-hemiparkinsonian rat model are used for standardized experiments. Here, we analyzed proteome changes of the striatum three months after 6-OHDA lesions of the nigral dopaminergic cell population. Striata were removed and proteins were separated by 2DE followed by differential spot analysis. Proteins in spots were identified by MALDI-TOF-MS. Most up-regulations of proteins were concerning energy metabolism in mitochondria. Proteins of calcium homeostasis like annexin A3, annexin A7, calbindin, calmodulin, calreticulin, and reticulocalbin 1 also were differentially regulated. Moreover, proteins involved in antioxidative mechanisms like superoxide dismutase, protein disulfide isomerase 1 and 3, N(G),N(G)-dimethylarginindimethyl-aminotransferase 2, and thioredoxin-dependent peroxide reductase were up-regulated. Interestingly, most cytoskeletal proteins belonging to the axon cytoskeleton and synapse were up-regulated pointing to long-distance axon remodeling. In addition, transcription factors, proteins of nucleic acid metabolism, chaperones, and degrading proteins (UCHL1) were up-regulated as well. In conclusion, the neurotoxin-induced proteome alterations indicate vivid long-distance remodeling processes of dendrites, axons, and synapses that are still ongoing even three months after perturbation, indicating a high plasticity and regeneration potential in the adult rat brain.
    Journal of Proteome Research 09/2010; 9(9):4671-87. · 5.06 Impact Factor
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    Oliver Schmitt, Harald Birkholz
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    ABSTRACT: To detect changes of cortical cytoarchitectonics, digital images of cortical laminations are analyzed. Cortical regions are transformed into a rectangular grid for subsequent evaluations. Transformations are realized by stepwise scanning using perpendicular testlines. 3D cytoarchitectonic data of the human brain at a histological resolution are not available and 2D sections deliver partial information only. The problem is to find an optimal scanning-technique that introduces a minimum of distortions and noise by the transformation of the curvilinear cortex to a rectangular presentation. In the past this was solved by constructing testlines dependent on the outlined cortical contours only. An advanced approach was to model the contours as electrically charged surfaces and to use the resulting field lines as testlines. However, local information of cell distributions were not considered. Hence a novel hybrid approach was developed which is able to construct significantly better testlines in cortical images with mixtures of columnar rich (local orientation rich) and orientation poor parts of strongly curved and large regions of the cerebral cortex. The novel hybrid approach is based on the computer vision methods such as the structure tensor and constrained anisotropic diffusion. In addition, the introduction of projective transformations yields a significant improvement of cortical fingerprints, thereby offering the possibility for detecting weakly pronounced regions of cytoarchitectonic transitions. The statistical evaluation of the novel hybrid approach confirms robustness. This technique can be generalized and applied to different types of cerebral cortex with any kind and amount of local orientation information. Microsc. Res. Tech. 2010. (c) 2010 Wiley-Liss, Inc.
    Microscopy Research and Technique 08/2010; · 1.59 Impact Factor

Publication Stats

1k Citations
342.85 Total Impact Points

Institutions

  • 2003–2014
    • University of Rostock
      • • Institut für Anatomie
      • • Faculty of Medicine
      Rostock, Mecklenburg-Vorpommern, Germany
    • St. Joseph Krankenhaus
      Berlín, Berlin, Germany
  • 2006–2013
    • Martin Luther University of Halle-Wittenberg
      • Institut für Anatomie und Zellbiologie
      Halle, Saxony-Anhalt, Germany
  • 1995–2012
    • University of Bonn
      • Poliklinik für Kieferorthopädie
      Bonn, North Rhine-Westphalia, Germany
  • 2006–2007
    • Medical University of Sofia
      • Department of Anatomy and Histology
      Ulpia Serdica, Sofia-Capital, Bulgaria
  • 1995–2003
    • Universität zu Lübeck
      • Institut für Anatomie
      Lübeck Hansestadt, Schleswig-Holstein, Germany
  • 1994–2001
    • University of Bonn - Medical Center
      Bonn, North Rhine-Westphalia, Germany